Impacts of Plantations of Exotic Forest Trees on Water Resources in Patagonia

阿根廷政府自1999年以来一直积极推动建立森林种植园。巴塔哥尼亚(阿根廷西南部)适宜种植林业的地区的气候与美国的太平洋西北地区(PNW)相似；来自PNW的针叶树在巴塔哥尼亚生长得很好，几种PNW树种，最著名的是黄皮松，在这些种植园中被广泛使用。这些种植园为一个经济受到残酷破坏的国家提供了许多潜在的好处；同时，它们也有可能造成深远的环境影响。迫切需要进行研究，以最大限度地提高效益，了解并有望缓解潜在的问题。该项目将研究黄松林对水资源的潜在影响。这在巴塔哥尼亚是至关重要的，那里的水是一种至关重要的有限资源。在三年的时间里，我们将通过测量树干流量(水分通过茎的移动)和土壤水分消耗来比较外来种植园和本地植被的水分利用和水分利用效率(生长与水分利用的比率)。我们还将使用土壤和植物茎中水中的氢和氧同位素来评估外来种植园和本地植被在土壤剖面中提取水分的位置。该项目将促进阿根廷和美国科学家在环境科学方面的教学和培训方面的合作努力。对该项目的支持也来自相当于阿根廷国家科学基金会的CONICET。

The government of Argentina has actively promoted establishment of forest plantations since 1999. The climate of the regions suitable for plantation forestry in Patagonia (southwest Argentina) is similar to the Pacific Northwest (PNW) of the United States; conifers from the PNW grow very well in Patagonia, and several PNW species, most notably ponderosa pine, are widely used in these plantations. These plantations offer many potential benefits to a country with a brutally damaged economy; at the same time they have the potential to cause profound environmental impacts. Research is urgently needed to maximize benefits and to understand, and hopefully mitigate, potential problems. This project will examine the potential impact of ponderosa pine plantations on water resources. This is critical in Patagonia, where water is a crucially limiting resource. Over a three-year period we will compare water utilization and water-use efficiency (the ratio of growth to water use) in exotic plantations and native vegetation by measuring sapflow (water movement through stems) and soil water depletion. We will also use hydrogen and oxygen isotopes in water of soils and plant stems to evaluate where water is extracted within the soil profile by exotic plantations and native vegetation. The project will develop a cooperative effort between scientists in Argentina and the U.S. in teaching and training students in environmental science. Support for this project also comes from CONICET, Argentina's equivalent of NSF.